Non-contact power transmission apparatus

ABSTRACT

A non-contact power transmission apparatus accurately determines the kind of object that is placed on the charging deck of the non-contact power transmission apparatus, and, only when a non-contact power receiving apparatus is placed on the power transmission apparatus, allows power transmission and data communication to take place, thereby accurately determining the state of the receiver side and efficiently controlling the transmission of power. In the power transmission apparatus, the power supplied to the non-contact power receiving apparatus is measured, and the output power of the wireless power signal output from two different cores is controlled, thereby allowing the charging operation to be stably conducted even if the non-contact power receiving apparatus is moved anywhere on the power transmission apparatus. The power transmission apparatus improves both the reliability of operation of the non-contact charging system, and the competitiveness of related products, such as portable terminals, battery packs and the like.

TECHNICAL FIELD

The present invention relates to a non-contact power transmissionapparatus, and more particularly to a non-contact power transmissionapparatus for transmitting electric energy in a wireless powertransmission manner, which detects an object placed on the charging deckthereof and enables power transmission and data communication only whena non-contact power receiving apparatus is present, thereby accuratelyperceiving the state of the receiver side and efficiently controllingthe power.

BACKGROUND ART

Generally, a battery pack is a kind of power supply that is charged withpower (electric energy) received from an external charger and suppliesthe power so that portable electronic devices, such as cellular phones,personal digital assistants (PDAs) and the like can be operated, andconsists of a battery cell which is charged with electric energy andcircuits for charging and discharging the battery cell (supplyingelectric energy to portable terminals).

The electrical connection between the battery pack, which is used in theportable terminals, and the charger for charging electric energy to thebattery pack may be achieved using a connector supply system, whichreceives the power from a regular power source and converts the voltageand current thereof to correspond to those of the battery pack, andsupplies the electric power to the battery pack via a connector of thecorresponding battery pack.

However, such a connector supply system has drawbacks, including instantdischarge owing to the difference in potential between the chargerconnector and the battery connector, the risk of fire and concomitantdamage due to fire caused by the presence of foreign substances,reduction in the life and performance of the battery pack, and the like.

To solve the above-mentioned problems, a non-contact charging system andcontrol method thereof using a wireless power transmission system wererecently proposed.

This non-contact charging system includes a non-contact powertransmission apparatus for wirelessly supplying electric power, anon-contact power receiving apparatus receiving the electric power fromthe non-contact power transmission apparatus and charging the batterycell with it, and the like.

Meanwhile, due to its non-contact nature, the non-contact chargingsystem conducts a charging operation while the non-contact powerreceiving apparatus is placed in the non-contact power transmissionapparatus.

Here, if foreign substances, such as a metal, are placed in thenon-contact power receiving apparatus, the foreign substances causeproblems such as abnormal power transmission, product damage due to firecaused by overload or the like.

The information disclosed in this Background of the Invention section isonly for the enhancement of understanding of the background of theinvention and should not be taken as an acknowledgment or any form ofsuggestion that this information forms the prior art that would alreadybe known to a person skilled in the art.

DISCLOSURE Technical Problem

To solve the above-mentioned problems, the present invention is directedto a non-contact power transmission apparatus formed to send out anasking signal via a power transmission coil to identify an object placedthereon, measure the standby time taken up to the time when a responsesignal is received, and compare the measured standby time with a setreference standby time to rapidly determine whether the object is aforeign substance or a non-contact power receiving apparatus of abattery pack or the like.

Meanwhile, since it is difficult to implement communication using anamplitude shift keying (ASK) method, which determines whether the objectplaced thereon is a foreign substance such as a metal or a non-contactpower receiving apparatus, if the amplitude of a signal is narrow underDC load modulation conditions, it cannot perceive the state of thereceiver side and fails to transmit power or control the transmission ofpower, thereby causing the problem of reduced power transmissionefficiency.

To solve this problem, the present invention is directed to anon-contact power transmission apparatus for wirelessly supplyingelectric power, which, upon ASK data communication with a non-contactpower receiving apparatus, which receives the supplied power and chargesa battery cell with it, uses Pulse Width Modulation (PWM) for smoothdata communication.

Further, the present invention is directed to a non-contact powertransmission apparatus using an ASK charging control module, which, evenunder DC load modulation conditions, accurately perceives the state ofthe receiver side and efficiently controls the power even when anon-contact power receiving apparatus is moved on the charging deckthereof.

Technical Solution

According to an aspect of the present invention, the non-contact powertransmission apparatus may include a primary core, which wirelesslysends out a wireless power signal to a non-contact power receivingapparatus having a secondary core, which is operated such that, when achange in the load of the primary core is detected, measures the delaytime from the output time of an asking signal, asking what the object onthe non-contact power transmission apparatus is, to the time of receiptof a response signal corresponding to the asking signal, the signalsbeing transmitted via the primary core, compares the measured time witha reference standby time, and, if the measured time is shorter than thereference standby time, determines that the object is a foreignsubstance, and if the measured time is longer than the reference standbytime, determines that the object is the normal non-contact powerreceiving apparatus, and sends out the wireless power signal.

In particular, the non-contact power receiving apparatus may receive thewireless power signal from the non-contact power transmission apparatus,compare the received signal with a reference voltage, and create a pulsesignal based on a duty rate that is set depending upon the comparisonresult and transmits the created signal to the non-contact powertransmission apparatus, which in turn controls the intensity of thetransmitted wireless power signal in correspondence with the transmittedpulse signal.

Further, the non-contact power receiving apparatus may include an IDtransmitter for transmitting and receiving code data of an AC signal,modulated in an AC modulation manner, via the secondary core, and thenon-contact power transmission apparatus may include a feedback circuitunit for extracting the code data of the AC signal from a DC signalapplied to the primary core when the code data are received by theprimary core.

Preferably, the non-contact power receiving apparatus may include acapacitor, connected in parallel with the power receiving core side ofthe secondary core to remove a DC signal component.

More preferably, the non-contact power receiving apparatus may furtherinclude a MOSFET serially connected with the capacitor, and the IDtransmitter inputs the operation voltage of the MOSFET to a gateterminal of the MOSFET in correspondence with the duty rate setdepending on the comparison result.

Further, the feedback circuit unit may include an RC filter circuitelectrically connected with one end of the primary core to remove the DCsignal component, and an amplifying circuit having an OP-AMPelectrically connected with the RC filter circuit.

Further, the primary core may include first and second powertransmission core sides and has a multi-layered structure having anoverlapping region in which the first and second power transmission coresides partially overlap each other.

According to another aspect of the present invention, the non-contactpower transmission apparatus may include a transmission module having aprimary core wirelessly sending out a wireless power signal to anon-contact power receiving apparatus having a secondary core, thetransmission module including a body case; a board provided in the bodycase and having a control module for sending out the wireless powersignal; a shielding plate provided on an upper portion of the board;first and second power transmission core sides provided on an upperportion of the shielding plate such that they are electrically connectedwith the control module, the first and second power transmission coresides partially overlapping each other; a light-emitting device fordisplaying the charging state provided on a side of the body case suchthat it is electrically connected with the control module; and a cover,which is coupled to the body case and on which the non-contact powerreceiving apparatus is placed.

Particularly, at least one of the first and second power transmissioncore sides may be formed into a bent form and the first and second powertransmission core sides are of a multi-layered structure in which theregion of the first core side, which overlaps the second core side, islaid on or below the region of the second core side, which overlaps thefirst core side.

Preferably, the overlapping region may be larger than the width of thewireless power receiving core of the wireless non-contact powerreceiving apparatus and smaller than the widths of the first and secondpower transmission core sides.

Further, the transmission module may include a fitting along whichanother transmission module detachably slides.

Further, the body case may be a support for a monitor.

Further, the transmission module may further include a power cableconnected to the power supply port provided in a monitor and throughwhich the power for operating the monitor is supplied.

Preferably, the power cable may be connected to a branching power cable,which supplies a regular power source to the monitor.

Further, the transmission module may include on another side of the bodycase a connection terminal to be connected to a connection boat for anOptical Disk Drive (ODD) of a monitor, the connection terminal beingelectrically connected with the control module mounted on the board.

Advantageous Effects

According to the above-mentioned construction, the present invention canaccurately determine the kind of object that is placed on the chargingdeck of the non-contact power transmission apparatus and, only when anon-contact power receiving apparatus is placed on the powertransmission apparatus, allows the power transmission and datacommunication to take place, thereby having the effect of preventingdamage by foreign substances from occurring to a device.

Further, even when the amplitude of a signal is small under the loadingconditions of DC load modulation, the present invention makes smoothdata communication possible, thereby accurately determining the state ofthe receiver side and efficiently controlling the transmitted power.

Further, the primary core of the non-contact power transmissionapparatus, which transmits a power signal using an induced magneticfield, is formed into a thin, planar spiral core structure provided noton a ritz core, but on a PCB core so that it can be easily mounted in anon-contact power transmission apparatus such as a non-contact charger,thereby increasing the ease of adaptation of the primary core to variousproducts. Still further, the primary core is constituted in amulti-layered structure, so that a charging operation can always becarried out regardless of where the non-contact power transmissionapparatus, such as a portable electronic device, is moved on thecharging deck.

Further, the power supplied to the non-contact power receiving apparatusis measured and the output power of the wireless power signal outputfrom the two different cores is controlled and corrected depending uponthe measurement result, thereby allowing the charging operation to beconducted stably.

Therefore, the present invention can improve both the reliability ofoperation of the non-contact charging system, comprising the non-contactpower receiving apparatus and the non-contact power transmissionapparatus, and the competitiveness of related products, such as portableterminals, battery packs and the like.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description of the Invention, which togetherserve to explain certain principles of the present invention.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic configuration view of a non-contact powertransmission apparatus in accordance with the present invention;

FIG. 2 is a detailed configuration view of another example of anon-contact power transmission apparatus in accordance with the presentinvention;

FIG. 3 is a circuit diagram of exemplary major parts of the non-contactpower transmission apparatus illustrated in FIG. 1;

FIG. 4 is a graphical diagram illustrating an exemplary feedback signalwhich is detected via a primary core and indicates the kind of objectplaced on the non-contact power transmission apparatus of FIG. 1;

FIG. 5 is a circuit diagram of exemplary major parts of the non-contactpower transmission apparatus of FIG. 1;

FIG. 6 is a graphical diagram illustrating a charging voltage of thenon-contact power receiving apparatus of FIG. 1 and exemplarytransmitted/received signals for controlling charging;

FIGS. 7 to 9 are flow diagrams illustrating exemplary methods ofcontrolling the non-contact power transmission apparatus in accordancewith the present invention;

FIGS. 10 and 11 are flow diagrams illustrating exemplary methods ofcontrolling the non-contact power receiving apparatus in accordance withthe present invention;

FIG. 12 is a configuration view of the construction of an exemplaryprimary core of the non-contact power transmission apparatus inaccordance with the present invention;

FIG. 13 is a configuration view explaining the step S117 of FIG. 9 andthe step S214 of FIG. 11;

FIG. 14 is a configuration view of the construction of another exemplaryprimary core of the non-contact power transmission apparatus inaccordance with the present invention;

FIG. 15 is an exploded perspective view illustrating the concept of atransmission module, in which major parts of the non-contact powertransmission apparatus are formed into a module in accordance with thepresent invention;

FIGS. 16 and 17 are views illustrating the state of the transmissionmodule of FIG. 15 in use;

FIGS. 18 to 20 are views illustrating the state of another transmissionmodule in use; and

FIG. 21 is a view illustrating the state of still another transmissionmodule in use.

BEST MODE

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments, it will beunderstood that the present description is not intended to limit theinvention(s) to those exemplary embodiments. On the contrary, theinvention(s) is/are intended to cover not only the exemplaryembodiments, but also various alternatives, modifications, equivalentsand other embodiments, which may be included within the spirit and scopeof the invention as defined by the appended claims.

The non-contact power transmission apparatus of the present invention isvariously applicable, and preferred embodiments thereof will now bedescribed in detail with reference to the accompanying drawings.

FIG. 1 illustrates a wireless power transmission system which includesthe non-contact power transmission apparatus 100 of the presentinvention for sending out a wireless power signal and a non-contactpower receiving apparatus 200 receiving the wireless power signal andcharging a battery cell with it.

The non-contact power transmission apparatus 100 includes a primary core110, an identifier 120, a wireless power transmission controller 130, aswitching controller 140, an operating driver 150, a series resonanceconverter 160, and a feedback circuit 170.

The primary core 110 consists of first and second power transmissioncore sides 111 and 113, which are connected in parallel with the seriesresonance converter 160.

The identifier 120 detects a change in the load of the primary core 110and determines whether the change is induced by the non-contact powerreceiving apparatus 200 or not. Thus, the identifier serves both todetect the change in the load and to analyze and process a data signalcode of an AC signal of the signals transmitted from the non-contactpower receiving apparatus 200.

The wireless power transmission controller 130 receives and checks thedetermination result from the identifier 120, and, if the change in theload is induced by the non-contact power receiving apparatus 200, sendsout a power control signal to the operating driver 150 via the primarycore 110 to transmit the wireless power signal.

Then, the controller 130 analyzes and processes the data signal filteredby the identifier 120 and correspondingly controls the operating driver150. In addition, the controller creates a data signal (e.g. an IDasking signal) and transmits it to the non-contact power receivingapparatus 200 via the primary core 110.

The switching controller 140 controls the switching operation of firstand second switches 141 and 142, which are connected between the seriesresonance circuit 160 and the first power transmission core side 111 andbetween the series resonance circuit and the second power transmissioncore side 112, respectively.

The operating driver 150 controls the operation of the series resonanceconverter 160 depending upon the intensity of the wireless power signalthat is to be transmitted.

The series resonance converter 160 creates a transmission power sourcefor creating a wireless power signal to be transmitted under the controlof the operating driver 150, and supplies it to the primary core 110.

That is, when the wireless power transmission controller 130 transmits apower control signal for transmitting a wireless power signal, which hasa required power value, to the operating driver 150, the operatingdriver 150 controls the operation of the series resonance converter 160to correspond to the transmitted power control signal, and the seriesresonance converter 160 applies to the primary core 110 a transmissionpower source, which corresponds to the required power value, under thecontrol of the operating driver 150, thereby transmitting a wirelesspower signal having the required intensity.

When the code data of an AC signal is received by the primary core 110,the feedback circuit 170 extracts the code data of the AC signal from aDC signal applied to the primary core 110. As illustrated in FIG. 3, thefeedback circuit 170 includes an RC filter circuit section 171, which iselectrically connected with ends of the first and second powertransmission core sides 111 and 112 of the primary core 110 to remove aDC signal component (low frequency component), and an amplifying circuitsection 172, which has an OP-AMP that is electrically connected with theRC filter circuit section.

That is, the low frequency signal, which is a DC signal component, isremoved by the RC filter circuit section 171 and the extracted AC signalcomponent is amplified by the amplifying circuit section.

Thus, it is possible to transmit and receive a low-amplitude signal.

The non-contact power receiving apparatus 200 to be supplied with powerby receiving the wireless power signal includes a power receiving coreside 211 of a secondary core 210, which creates induced power using thetransmitted wireless power signal; a rectifier 220, which rectifies theinduced power; and a battery cell module 230, which charges a batterycell with the rectified power.

This battery module 230 includes a protection circuit, such as anovervoltage and overcurrent preventing circuit, a temperature detectingcircuit and the like, and a charging management module, which collectsand processes information such as the charged state of the battery cellor the like.

The non-contact power receiving apparatus 200 further includes awireless power receiver controller 240, which checks the current inducedto the power receiving core 211 of the secondary core 210 and requeststhe control of the intensity of a wireless power signal based on theinformation on the charging of the battery cell, which is collected andprocessed by the battery cell module 230, and an ID transmitter 250,which, via the secondary core 210, transmits and receives the code dataof an AC signal modulated in an AC modulation manner.

As illustrated in FIG. 5, the non-contact power receiving apparatus 200further includes a capacitor C, which is connected in parallel with thepower receiving core 211 of the secondary core 210 to remove a DC signalcomponent, and a MOSFET, in which a drain terminal is serially connectedwith the capacitor.

The MOSFET performs on/off control under the control of the IDtransmitter 250. The ID transmitter 250 inputs the operation voltage ofthe MOSFET to the gate terminal of the MOSFET in correspondence with aduty rate, which is set to correspond to the control request for theintensity of the wireless power signal by the wireless power receivercontroller 240.

That is, when the ID transmitter 250 inputs an on-signal and anoff-signal, which correspond to the operation voltage, to the gateterminal, the MOSFET creates and outputs a pulse width modulated (PWM)signal corresponding to voltage input to the gate terminal, and the PWMsignal is transmitted to the non-contact power transmission apparatus100 via the power receiving core 211.

The detailed embodiment of the non-contact power transmission apparatus100 is illustrated in FIG. 2.

In the figure, the non-contact power transmission apparatus 100 issupplied with power, via a power supply port 181, from an adaptersupplied with a regular power source, a power source of a USB port of aportable terminal such as a notebook, or the like.

The apparatus 100 further includes a current detector 191 that detectsthe internal current of the apparatus 100, and a temperature detector192 that detects the internal temperature of the apparatus 100 duringthe charging process, so that if overheating, overvoltage or overcurrentoccurs, the operation can be stopped.

The battery cell module 230 of the non-contact power receiving apparatus200 further includes a charging circuit 231 for charging a battery cell,a gauge circuit 232, for checking the charged quantity, and a chargingmonitoring circuit 233, for monitoring the charging state.

A display 193 is further provided to display the state of operation ofthe non-contact power transmission apparatus 100 and the charging stateof the non-contact power receiving apparatus 200.

The method of charging a non-contact charging system using the corestructure for the wireless power transmission will now be described.

First, the operation of the non-contact power transmission apparatus 100will be described with reference to FIGS. 7 to 9. A standby mode ismaintained, wherein the switching controller 140 of the apparatus 100keeps the first and second switches 141 and 142 in an OFF state, and theidentifier 120 detects the change in load of the first and second powertransmission core sides 111 and 112 of the primary core 110 (S101).

In the standby mode 5101, when the non-contact power receiving apparatus200 is placed on the non-contact power transmission apparatus 100, achange in the magnetic field of the first and second power transmissioncore sides 111 and 112 occurs, and the identifier 120 detects the change(S102).

When the change in the load is detected, the identifier 120 informs thewireless power transmission controller 130 of this, and, as illustratedin FIG. 4, the controller 130 measures the delay in the receipt of theresponse signal (a reflected signal in the case where a foreignsubstance is present) by the primary core 110 with reference to thetransmitted signal fref (S103).

When the delay in the receipt of the response signal is measured, themeasured time is compared with a reference time (“Tfb” in FIG. 4)(S104). If the measured time is longer than the reference time (“Tfb1”in FIG. 4), it is determined that a normal non-contact power receivingapparatus 200 is present (S106), whereas, if the measured time isshorter than the reference time (“Tfb2” in FIG. 4), it is determinedthat a foreign substance is present (S107).

The determination is a primary determination reference, and thefollowing identification process also helps distinguish between foreignsubstances and non-contact power receiving apparatus.

When it is first determined that an object is a non-contact powerreceiving apparatus 200 based on a signal received via the identifier120, the wireless power transmission controller 130 transmits, via theprimary core 110, a signal requesting a header ID (S108).

Here, the header ID means a code on a header of an ID code.

Meanwhile, as illustrated in FIG. 10, in the standby mode for charging abattery cell (S201), when the header ID requesting signal is received(S202), the non-contact power receiving apparatus 200 transmits theheader ID code via the power receiving core 211 (S203).

When the header ID code is received in the primary core 110, theidentifier 120 determines that the object is the non-contact powerreceiving apparatus 200, and, if no response signal is received, theidentifier determines that the object is a metallic foreign substance(S109).

If the object is determined to be a foreign substance, a user isinformed that the foreign substance is detected, using letters orillumination via an output device such as an LCD or an LED (S111). Ifthe object is determined to be a non-contact power receiving apparatus200, a signal requesting a full ID is transmitted via the primary core110 (S110).

Here, the full ID means the full code of an ID code.

Meanwhile, in the standby mode for charging a battery cell (S201), whenthe full ID requesting signal is received (S202), as illustrated in FIG.10, the non-contact power receiving apparatus 200 transmits the full IDcode via the power receiving core 211 (S203).

When the full ID code is received, the identifier 120 checks this(S112). When a normal ID code is received, the identifier transmits awireless power signal to the non-contact power receiving apparatus 200(S113). When the received ID code is not normal, the user is informed ofthe occurrence of an ID error (S114).

Here, although some of the elements of the non-contact powertransmission apparatus 100 to be operated for the transmission of an IDcode requesting signal and the reception of a response signal are notexplained, they have already been explained through the description ofthe charging system of the present invention. Further, unnecessarilyrepetitive explanations will of course be omitted in the followingdescription.

Meanwhile, if an ID code is received by the first power transmissioncore side 111, the wireless power transmission controller 130 transmitsa switching control signal to the switching controller 140 to turn onthe first switch 141 and turn off the second switch 142, and transmitthe power control signal to the operating driver 150 (S193), therebysending out a wireless power signal via the first power transmissioncore side 111.

Here, the output power of the transmitted wireless power signal istransmitted corresponding to a reference power value, which correspondsto a voltage which can be induced into the input voltage (e.g. 4.5V to5.5V) required by the non-contact power receiving apparatus 200.

If an ID code is received to the second power transmission core side112, the wireless power transmission controller 130 transmits aswitching control signal to the switching controller 140 to turn off thefirst switch 141 and turn on the second switch 142, and transmit thepower control signal to the operating driver 150, thereby sending out awireless power signal via the second power transmission core side 112.

If the power receiving core 211 is positioned in the overlapping regionshown in FIG. 12, when the first and second power transmission coresides 111 and 112 receive an ID at the same time, the wireless powertransmission controller 130 transmits a switching control signal to theswitching controller 140 to turn on the first and second switches 141and 142 and transmits a power control signal to the operating driver150, thereby transmitting a wireless power signal via the first andsecond power transmission core sides 111 and 112.

Here, when the first and second power transmission core sides 111 and112 respectively transmit the wireless power signal with output powercorresponding to a reference power value, excessive voltage can beinduced to the power receiving core 211.

Thus, in the case where the first and second power transmission coresides 111 and 112 receive the ID at the same time, it is preferred thatthe wireless power signal be transmitted while the sum of the outputpower of the first power transmission core side 111 and the output powerof the second power transmission core side 112 is controlled tocorrespond to the reference power value.

When the wireless power signal is received by the non-contact powerreceiving apparatus 200 according to the above process (S204), thenon-contact power receiving apparatus 200 charges a battery cell usingelectrical energy induced to the power receiving core 211 (S205).

As illustrated in FIG. 11, the non-contact power receiving apparatus 200checks the charging state of the battery cell (S206) and ascertainswhether or not the battery cell is fully charged (S207) and whether ornot a gauge has changed (S211). Then, in order to accomplish stablecharging, which is an object of the present invention, the apparatus 200detects voltage induced to the power receiving core 211 and determinesif the detected voltage is within the range of the input voltage (e.g.4.5V to 5.5V) that is required for the charging operation (S213 andS215).

As a result of the checking, if the battery cell is fully charged(S207), the battery cell module 230 transmits, to the non-contact powertransmission apparatus 100 via the ID transmitter 240, a power off code,modulated in an AC modulation manner (S208), and terminates the chargingoperation (S209), and, if the gauge is changed (S210), a gauge code istransmitted (S211).

As a result of the determination, if the induced voltage is not withinthe set range, the non-contact power receiving apparatus 200 transmits apower control requesting signal to the non-contact power transmissionapparatus 100 (S240).

For example, as illustrated in FIG. 13, if the power receiving core 211is moved outside and voltage is induced which is lower than the setrange (S213), a power up code is transmitted (S214), and if the powerreceiving core 211 is positioned in the overlapping region of FIG. 12and voltage, which is higher than the set range, is induced to the powerreceiving core 211 by the wireless power signal simultaneouslytransmitted from the first and second power transmission core sides 111and 112 (S215), a power down code is transmitted (S216).

When the respective codes are transmitted as such, the non-contact powerreceiving apparatus 200 monitors the intensity and other characteristicsof the wireless power signal transmitted from the non-contact powertransmission apparatus 100 (S212).

When the power control code is received by the primary core 110 of thenon-contact power transmission apparatus 100 (S115), the feedbackcircuit 170 extracts a corresponding code from a signal (a transmittedpower signal of a DC component and a code signal of a received ACcomponent) induced to the primary core (110).

The wireless power transmission controller 130 receives and analyzes theextracted code, and if the code is the power off code (S116), displays afully charged state via LED or LCD (S119), if the code is the gauge code(S118), the charging state is output (S119), if the code is the power upcode (S121), the output power of the corresponding power transmissioncore is increased (S122), and if the code is the power down code (S123),the output power of the corresponding power transmission core is reduced(S124).

The step S115 of FIG. 9 is performed in order to determine whether ornot charging is to continue.

For example, as illustrated in FIG. 6, if sensing voltage (Vsense inFIG. 5) branching from a voltage (DC in FIG. 5) for charging a batterycell is lower than a reference voltage (Vset), the ID transmitter 250inputs a pulse signal with a duty rate that is larger than a duty ratecorresponding to the reference voltage, to the gate terminal of theMOSFET. The MOSFET creates a power up code and transmits it to thenon-contact power transmission apparatus 100 while performing ON and OFFoperations in correspondence with the pulse signal input to the gateterminal, and a wireless power signal to be transmitted is received tothe wireless power receiver controller 240 after the delay time (Td)passes.

Here, ‘Tx’ and ‘Rx’ in FIG. 5 indicate the transmission and reception ofa signal from and to the non-contact power transmission apparatus 100.

The wireless power transmission controller 130 of the non-contact powertransmission apparatus 100 calculates a corrected power valuecorresponding to the received power control requesting signal(respective core signals), applies the corrected power value to thereference power value and transmits a wireless power signal via at leastone of the first and second power transmission core sides 111 and 112,so that stable charging can be performed irrespective of the position ofthe non-contact power receiving apparatus 200.

Meanwhile, the primary core 110 of the non-contact power transmissionapparatus 100 transmitting a wireless power signal using a wirelesspower transmission method, as shown in FIG. 12, comprises the first andsecond power transmission core sides 111 and 112 and a shielding section115. FIG. 12 illustrates that the power receiving core 211 of thesecondary core 210 is moved on the first and second power transmissioncore sides 111 and 112.

The first and second power transmission core sides 111 and 112 areformed in a PCB pattern type, and include a first single region, whichbelongs only to the first power transmission core side 111, a secondsingle region, which belongs only to the second power transmission coreside 112, and an overlapping region, where the first and second powertransmission core sides 111 and 112 overlap each other.

Thus, even when the power receiving core 211 of the secondary core 210is moved, as shown in FIG. 12, power can be continuously supplied.

Further, it is preferred that the width W1 of the overlapping regionwhere the first and second power transmission core sides 111 and 112overlap each other be set greater than the width W2 of the powerreceiving core 211, so that even when the power receiving core 211 ismoved, it remains within the receiving range of the wireless powersignal by the first or second power transmission core sides 111 or 112.

Meanwhile, the shape and construction of the above-mentioned primarycore 110 and the first and second power transmission core sides 111 and112 may be variously modified by a person skilled in the art.

For example, the power transmission core 300 of the primary core shownin FIG. 14 may include a double-structured induction section (noreference number) of upper and lower core layers 310 and 330 on a PCBbase 340.

The induction section comprises a power transmission (PT)-PCB corehaving a planar spiral core structure (PSCS). That is, the PT-PCB coreis formed such that a single-layered or multi-layered copper planarspiral core is formed on a PCP (PCB having a Copper Clad Laminate (CCL),Flexible CCL (FCCL) or the like).

The upper and lower core layers 310 and 330 are each composed of upperunit cores 311 and lower unit cores 331. The unit cores may be modifiedinto structures such as a circle, an oval, a triangle, a rectangle, apolygon or the like by a person skilled in the art. In FIG. 14, apentagonal core structure is illustrated.

The upper and lower unit cores 311 and 331 are composed of copper, and aPSR coating layer is formed on the upper and lower core layers 310 and330 in order to protect them (from damage, corrosion or the like).

Here, if an Electroless Gold Plating Layer (EGPL) is formed on the upperand lower core layers 310 and 330, the efficiency of the inducedmagnetic field is improved, so that the power transmission rate can begenerally improved.

Under the PCB base 340, a Hanrim Postech Electro-magnetic Shield (HPES)350 is provided in order to prevent an electronic device of an appliancefrom being influenced by the induced magnetic field. The HPES 350consists of a shield panel 351, a shield mesh 352, and a metal film 353,which are sequentially laminated on one another.

Here, the shield panel 351 is composed of 25 parts to 55 parts by weightof polyurethane with 55 parts to 75 parts by weight of sendust, whereinsendust is a highly permeable alloy composed of aluminum, silicon, ironor the like, so that the transmission shield panel is constructed usingthe combination of high shielding performance sendust and polyurethane.

Meanwhile, if the composition of sendust is below 55 parts by weight,the shielding performance may be degraded, whereas if it is more than 75parts by weight, the performance is not improved in proportion with theinput quantity.

The shield mesh 352 serves to reduce the occurrence of eddy current byinduced electromotive force created by the induced magnetic field, andis made up of a net-type structured polyester coated with an eddycurrent reduction composition composed of 35 parts to 45 parts by weightof Zn with 55 parts to 65 parts by weight of Ni, the net structure beingmade of metal net of 100 meshes to 200 meshes, preferably 135 meshes.

The metal film 353 consists of Al and serves to finally block themagnetic field from the lowermost side of the HPES 350 so that it doesnot affect a circuit or the like.

When the layer is composed of the plurality of unit cores, the wirelesspower transmission controller 130 can control the respective unit coresindividually so that it is obvious that the series resonance converter160 is constituted in correspondence with the respective unit cores.

The non-contact power transmission apparatus 100 can be activated bypower supplied from a regular power source, a USB port of a notebook,etc. That is, it can be activated by power from various kinds ofelectronic devices.

Reference will now be made to the non-contact power transmissionapparatus 100 of the present invention when actually adapted toelectronic devices.

FIG. 15 is an exploded perspective view illustrating the concept of atransmission module 10 in which major parts of the non-contact powertransmission apparatus 100 are formed into a module in accordance withthe present invention, wherein the transmission module includes a bodycase 11, a board 12, a shielding plate 13, a first power transmissioncore 14, a second power transmission core 15, and a cover 16.

The body case 11 includes a hollow section (not designated), in whichall of the remaining elements are housed, and a power supply connector(not shown) via which a typical external power source is supplied.

The board 12 comprises a printed circuit board (PCB), in which therespective elements of the non-contact power transmission apparatus 100shown in FIG. 1 are mounted in a module form.

The shielding plate 13 serves to protect electronic elements on theboard 12 from the effects of the wireless power signal transmitted bythe first and second power transmission core sides 14 and 15. It may bemade of various kinds of materials and have various constructions, asdetermined by a person skilled in the art.

The first and second power transmission core sides 14 and 15 are formedin a PCB pattern and have a double-core structure, in which two coresides partially overlap each other, as illustrated in FIG. 15, the twocore sides respectively transmitting the wireless power signal.

The cover 16 is coupled to the upper portion of the body case 11 so thatthe non-contact power receiving apparatus, such as a portable terminalP, a battery pack B or the like, is placed thereon. The cover iscomposed of a material through which the wireless power signals from thefirst and second power transmission core sides 14 and 15 can betransmitted out.

A light emitting diode (LED) 11 a is provided on a side of the body case11 to display the charging state of the non-contact power receivingapparatus.

As shown in FIG. 15, the transmission module with overlapping doublecores comprises two different transmission modules 10 and 10, which arearranged such that one transmission module 10′ is provided with afitting 11 b′, along which another transmission module 10 detachablyslides, thereby enabling simultaneous charging of both the portableterminal P and the battery pack B, as shown in FIG. 16.

In the case in which only the portable terminal P is charged, asillustrated in FIG. 17, the transmission module 10 for charging thebattery pack B is moved into the other transmission module 10′, therebysaving space.

Here, unexplained reference number 11 a′ denotes a light emitting diodeprovided on a side of another transmission module 10′.

Meanwhile, since the case exists in which the non-contact powerreceiving apparatus 200, such as the battery pack B, is occasionallymoved during the charging process, as shown in FIG. 16, in order toallow the charging process to be conducted stably even if the apparatus200 moves in this way, the first and second power transmission coresides 14 and 15 are provided in an overlapping form.

That is, the first and second power transmission core sides 14 and 15,which are the primary cores provided in the transmission module 10 fortransmitting a wireless power signal, are arranged on the shieldingplate 13 such that they have a first single region of only the firstpower transmission core side 14, a second single region of only thesecond power transmission core side 15, and an overlapping region, inwhich the first and second power transmission core sides 14 and 15overlap each other.

Thus, even if a power receiving core Ba of a secondary core is moved asshown in FIG. 15, power can be continuously supplied.

Meanwhile, the transmission module 10 of the non-contact powertransmission apparatus 100 can be adapted to a monitor M or the like asshown in FIGS. 18 to 20.

That is, a transmission module 10″ may be provided in which the bodycase 11 of FIG. 1 is used as a monitor support 11″ and the board 12, theshielding plate 13, the first and second power transmission core sides14 and 15, and the cover 16 are provided in the space near the monitorsupport 11″, so that, as shown in FIG. 19, a portable terminal P isplaced on the cover 16 and a battery in the portable terminal P ischarged.

Further, the transmission module 10 of the present invention isconnected with a power supply port Ma, which is provided on a side ofthe monitor M, via a power cable C, so that it can be supplied withdriving power distributed from the monitor M.

Further, as illustrated in FIG. 20, the transmission module 10 can bedirectly supplied with regular power by connecting a power cable C to aconnection terminal, which branches from a power cable C′ that suppliesregular power to the monitor M.

Further, as illustrated in FIG. 21, a connection terminal T is providedon another side of the body case such that it is connected to aconnection port Na of an optical disk drive (ODD) of a notebook N,whereby drive power of the transmission module Na can be suppliedthrough the connection port Na.

As set forth before, the transmission module 10 constituted to beconnected with the monitor M and the notebook N is provided with a powersupply unit (not shown) depending upon the power source that is suppliedaccording to the state of use, but this power supply unit is not limitedto any specific form, and may be variously configured according to thekinds of input power sources and demand by a person skilled in the art.

In describing the respective embodiments, while like parts have beendenoted with like numerals, in the case of describing like parts asdifferent parts for the convenience of explanation, such as when clearlydividing or individually explaining the respective embodiments, theyhave been denoted with different numerals.

The non-contact charging system including the non-contact powertransmission apparatus of the present invention has been describedabove. It is understood that the technical construction of the presentinvention may be modified to have different forms without departing fromthe spirit and essential features of the present invention by thoseskilled in the art.

Therefore, the above-mentioned embodiments are provided only forillustrative purposes in all aspects, but are not limited thereto. Itshould be construed that the scope of the present invention is definednot by the above detailed description, but by the appended claims, andthat the described embodiments and all variations or modifications thatcan be deduced from equivalents interpreted from the claims fall withinthe scope of the present invention.

The invention claimed is:
 1. A method for controlling a powertransmission in a non-contact power transmission device, the methodcomprising: detecting a load change of a primary core in the non-contactpower transmission apparatus when an object is placed on the non-contactpower transmission apparatus; transmitting a requesting signal to theobject via the primary core if a load change is detected; receiving aresponse signal via the primary core in response to the requestingsignal and measuring a delay time between the time of outputting therequesting signal and the time of receiving the response signal;confirming whether the object is a non-contact power receiving apparatusby comparing the delay time with a reference time; receiving a pulsesignal according to the comparison result of the non-contact powersignal and a reference voltage, the non-contact power signal beingtransmitted from the non-contact power receiving apparatus; andcontrolling an intensity of the non-contact power signal according tothe pulse signal.
 2. The method of claim 1, further comprising: afterconfirming that the object is a non-contact power receiving apparatus,transmitting an ID requesting signal to the object to re-confirm whetherthe object is a non-contact power receiving apparatus through an IDresponse signal received in response to the ID requesting signal; andtransmitting a non-contact power signal to the non-contact powerreceiving apparatus if the object is confirmed to be a non-contact powerreceiving apparatus.
 3. The method of claim 2, wherein transmitting theID requesting signal to the object comprises: transmitting a header IDrequesting signal; and transmitting a full ID requesting signal if aheader ID code is received from the non-contact power receivingapparatus.
 4. The method of claim 2, further comprising: receiving apulse signal according to the comparison result of the non-contact powersignal and a reference voltage, the non-contact power signal beingtransmitted from the non-contact power receiving apparatus; andcontrolling an intensity of the non-contact power signal according tothe pulse signal.
 5. The method of claim 4, wherein the pulse signalcomprises any one of a power-off code, a gauge code, a power-up code,and a power-down code.
 6. The method of claim 4, further comprisingextracting a code data from the pulse signal via a feedback circuitunit.
 7. The method of claim 6, wherein the feedback circuit unitcomprises: an RC filter circuit electrically connected with an end ofthe primary core to remove a DC signal component; and an amplifyingcircuit having an OP-AMP electrically connected with the RC filtercircuit.
 8. The method of claim 2, wherein the primary core comprises afirst power transmission core and a second power transmission corepartially overlapping with the first power transmission core.
 9. Themethod of claim 8, wherein the overlapping region between the first andsecond power transmission cores is greater than a width of a secondarycore of the non-contact power receiving apparatus and smaller than thewidths of the first and the second power transmission cores.
 10. Themethod of claim 8, wherein transmitting the ID requesting signal to theobject comprises transmitting the ID requesting signals to thenon-contact power receiving apparatus via the first and second powertransmission cores to re-confirm whether the object is a non-contactpower receiving apparatus.
 11. The method of claim 10, whereintransmitting the non-contact power signal to the non-contact powerreceiving apparatus comprises transmitting the non-contact power signalto the non-contact power receiving apparatus via at least one of thefirst and second power transmission cores if the ID response signals arereceived from both the first and second power transmission cores inresponse to the ID requesting signal.
 12. A non-contact powertransmission apparatus comprising: a primary core configured to transmita non-contact power transmission signal and an ID requesting signal; anID identifier configured to detect a load change of the primary core,the load change being generated when an object is placed on or near theprimary core; and a power transmission controller configured to transmita requesting signal to the object via the primary core due to beingplaced on if the load change is detected by the ID identifier, toreceive a response signal generated in response to the requesting signalvia the primary core, to measure a delay time between the transmissiontiming of the requesting signal and the receiving timing of the responsesignal, and to confirm whether the object is a non-contact powerreceiving apparatus by comparing the delay time with a reference time,to receive a pulse signal according to the comparison result of thenon-contact power signal and a reference voltage, the non-contact powersignal being transmitted from the non-contact power receiving apparatus;and to control an intensity of the non-contact power signal according tothe pulse signal.
 13. The apparatus of 12, further comprising: a seriesresonance converter configured to transmit the non-contact powertransmission signal to the primary core; and an operating driverconfigured to adjust an intensity of the non-contact power transmissionsignal by controlling the series resonance converter, wherein the powertransmission controller is configured to transmit an ID requestingsignal to the non-contact power receiving apparatus to reconfirm whetherthe object is a non-contact power receiving apparatus through an IDresponse signal generated in response to the ID requesting signal, andtransmit a power control signal for controlling the operating driver ifthe object is reconfirmed to be a non-contact power receiving apparatus.14. The apparatus of claim 13, wherein the power transmission controlleris configured to transmit a header ID requesting signal and transmit afull ID requesting signal if a header ID code is received from the powerreceiving apparatus.
 15. The apparatus of claim 13, wherein the powertransmission controller is configured to: receive a pulse signalaccording to the comparison result of the non-contact power signal and areference voltage, the non-contact power signal being transmitted fromthe non-contact power receiving apparatus; and control an intensity ofthe non-contact power signal according to the pulse signal.
 16. Theapparatus of claim 15, wherein the pulse signal comprises any one of apower-off code, a power-up code, a gauge code, and a power-down code.17. The apparatus of claim 16, further comprising a feedback circuitunit configured to extract a code data from the pulse signal.
 18. Theapparatus of claim 17, wherein the feedback circuit unit comprises: anRC filter circuit electrically connected with an end of the primary coreto remove a DC signal component; and an amplifying circuit having anOP-AMP electrically connected with the RC filter circuit.
 19. Theapparatus of claim 12, wherein the primary core comprises a first powertransmission core and a second power transmission core partiallyoverlapped with the first power transmission core.
 20. The apparatus ofclaim 19, wherein an overlapping region between the first and secondpower transmission cores is greater than a width of a secondary core ofthe non-contact power receiving apparatus and smaller than the widths ofthe first and second power transmission cores.
 21. The apparatus ofclaim 19, wherein the power transmission controller is configured totransmit ID requesting signals to the non-contact power receivingapparatus via the first and second power transmission cores, andtransmit non-contact power signal to the non-contact power receivingapparatus via at least one of the first and second power transmissioncores if the ID response signals are received in response to the IDrequesting signal.